I have 7 tiger barbs in a 55g new tank. All my water parameters are good and all look fine, but one will not leave his "space" around the ship decoration to eat. He is not very aggressive -- will not chase off other barbs if they come near. If they chase him he swims away and back to his domain as quickly as possible. He has no signs of illness; eyes bright, swims normally, no spots or gasping or anything else I have read about. He ate the first day, but that was before he had decided to guard the boat. He has missed only 2 feedings so far --should I worry
